On the basis of the Meiyu characteristic variable data at 37 stations in the Changjang-Huaihe River Valley from 1954 to 2001,the temporal evolution and spatial distribution of Meiyu characters are investigated in terms of harmonic analysis,empirical orthogonal function(EOF) and maximum entropy spectrum analysis and so on.Results show that temporal-spatial distributions of Meiyu characteristic variables are not homogeneous in the Changjiang-Huaihe River Valley.There are prominent interannual quasi-three years and interdecadal(10 years) variabilities in variations of Meiyu characteristic variables,and there are also positive or negative correlations between those interdecadal variations.The duration,rainfall and rainfall rate of Meiyu are positively/close correlated(P<0.001) and except the onset date,the end date,rainfall and duration of Meiyu all showed an increasing long-term trend.